Change of Contract

Working remote where my employer provides me with free accommodation and Utilities. Employer now wants to change my contract to include paying rent and utilities . Am I obliged to sign? Or Does my employer need to wait until my contract ends ?

Generally speaking, contracts usually have a clause saying that changes have to be agreed in writing by both parties, but even if this wasn't there, unless the contract states that the employer can change the contract unilaterally, then no, you are not obliged to sign or agree to a change in the contract. The whole purpose of a contract is to set the terms of engagement for the term of the contract.